Question

This is breaking my head, I have 2 functions
1) to get an ID
2) to call a second function with the ID which was retrieved.

Now I need to combine them in one function ,but obviously the 2nd function gets
called before GetSelectedID() has returned

function FillControl() {
        var iSelectedID  = GetSelectedID();
        SetControlValuesWithSelectedID(iSelectedID);
}

function GetSelectedID() {
                $.ajax({
                    url: '123.ashx',
                    type: 'POST',
                    contentType: 'application/json',
                    success: function (data1) {
                            return data1;
                    }
                });
            }

Please help to get the second function to be called only once first function has been called.

Answer 1

Your GetSelectedID() function is asynchronous, as it performs an AJAX request. It will return immediately, but iSelectedID will only be available some time later.

You can pass a callback function to GetSelectedID(), call that function from the success callback passed to $.ajax(), and relocate the call to SetControlValuesWithSelectedID in that function:

function GetSelectedID(callback)
{
    $.ajax({
        url: '123.ashx',
        data: PassingObj,
        type: 'POST',
        contentType: 'application/json',
        success: function(data1) {
            callback(data1);
        }
    });
}

Then:

function FillControl()
{
    GetSelectedID(function(iSelectedID) {
        SetControlValuesWithSelectedID(iSelectedID);
    });
}